As the size of semiconductor devices decrease, connecting on-chip electrical signals to off-chip pads or pins becomes increasingly challenging, especially while trying to increase the active circuit region of the semiconductor device. Part of the challenge includes designing semiconductor devices that conform to “design rules.” Design rules are a series of parameters provided by semiconductor manufacturers and specify certain physical requirements for the spacing and width of semiconductor elements. Some of the design rules require a minimum separation between the active circuit region, bonding pads, and the edge of a semiconductor device.
FIG. 1A is a planar top view of a convention semiconductor device 100. Semiconductor device 100 comprises active circuit region 110 and bonding pad region 120. Distances 126, 127, 128 and 129 are examples of distances that are subject to design rules. FIG. 1B is a planar top view of a conventional semiconductor device 150 which comprises active circuit region 160 and bonding pad region 170. In semiconductor device 150, bonding pads 175 are formed along one side of active circuit region 160, instead of surrounding the active region, as seen in FIG. 1A.
One example of a space critical application of semiconductor devices is CMOS image sensors used in endoscopes. It is desirable for endoscopes to be as small as possible (while still maintaining imaging quality) in order to be minimally-invasive. In endoscope and other applications, configurations and layouts to route on-chip electrical signals off-chip while increasing the active circuit region of the chip are desirable.